The present invention relates to construction of loading docks and particularly loading docks having a dock leveler mechanism.
A loading dock provides a surface for loading and unloading cargo to and from the bed of a hauling vehicle. In a typical loading dock, a dock ramp inclines downward to meet the loading dock entrance. The dock ramp is at an elevation below the entrance to the loading dock so that the truck bed will be as close to the elevation of the loading dock floor as possible. However, the cargo beds of the hauling vehicles are not uniform, so there is often a step up or down form the loading dock to the vehicle cargo bed.
Dock levelers are commonly used in a loading dock environment to provide a bridge between the dock and the bed of the truck. Most typically, dock levelers are mounted within a pit at a level lower than the floor of the warehouse dock. The dock levelers include a deck that is hydraulically, mechanically or electrically extended so that the front lip of the deck is aligned with the bed of the truck. The rear of the deck is aligned with the dock floor to provide a smooth path for unloading product from the truck. The dock leveler can be retracted within the pit, with the deck generally co-extensive with the dock floor.
A typical dock leveler is described and shown in U.S. Pat. No. 4,928,340, issued on May 29, 1990, the disclosure of which is incorporated herein by reference. The dock leveler includes a frame structure that supports a lifting element, such as a hydraulic cylinder. The deck is pivotably supported on the frame structure at the inboard end of the leveler pit. The front lip can be hingedly mounted to the front end of the movable deck to provide a smooth transition from the truck bed to the deck. The deck is pivoted so that the leading edge of the deck is aligned at the height of the bed of a truck positioned at the end of the dock ramp.
As indicated above, most typically dock levelers are mounted within a pit below the level of the loading dock floor, but above the level of the dock ramp. The pit, like the building floor, and often the building walls, is formed of concrete. In the construction of a building having a loading dock, the practice has been to construct the building walls and form and pour the building floor. The loading dock pit is excavated before the floor is poured and forms are used to keep the pit clear. The excavated pit can then be formed and the pit walls poured. Once the poured leveler pit walls have cured, the dock leveler mechanism can be mounted within the pt.
This common approach to forming a dock leveler pit is very time consuming and labor intensive. Each pit requires about 4-5 days from trenching until the concrete has set sufficiently to install the leveler mechanism. Since each pit must be individually formed and poured, a multi-bay warehouse can take many days to complete. In addition the time delays inherent in this common process, the material and labor costs can be extreme. Moreover, since the dock leveler pit is poured separate from the building slab, forming errors can occur.
Pre-cast concrete structures are becoming more prevalent in industrial building. For instance, many warehouse building are formed of pre-cast wall panels. What is needed is a pre-cast dock leveler pit that eliminates the cost, labor and time delay associated with the traditionally poured pit.